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VLI publikatsioonid

Selle valdkonna püsiv URIhttp://hdl.handle.net/10492/3354

Sirvi

Sirvi VLI publikatsioonid Autor "Andreson, Helena" järgi

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  • Pisipilt
    Kirje
    Exopolysaccharides production by Lactiplantibacillus plantarum strains isolated from industrial rye bread sourdoughs : [presentation]
    (Estonian University of Life Sciences, 2026) Lutter, Liis; Pikkel, Naatan; Ben Othman, Sana; Andreson, Helena
    Exopolysaccharides (EPS) are high-molecular-weight polysaccharides synthesized by microorganisms, including lactic acid bacteria (LAB), and are recognized for their impact on both technological and functional attributes of fermented foods. EPS contribute to improved texture, viscosity, water retention, and emulsion stability, while reducing syneresis, and may also exert bioactive effects such as antioxidant, immunomodulatory, anti-cancer, and modulatory activities on gastrointestinal and lipid metabolism. Within LAB, Lactiplantibacillus plantarum is of particular interest owing to its ability to produce EPS with both technological and functional significance. In sourdoughs, preserving microbial diversity in traditional starters is crucial, as these ecosystems harbor unique LAB strains with functional traits that are increasingly lost to uniform commercial cultures. The aim of this study was to characterize the EPS-producing capacity of L. plantarum strains isolated from decades-old, continuously propagated rye sourdoughs and to compare them with a commercial reference strain, thereby assessing their potential as technologically and functionally valuable starter culture candidates. A total of ten strains from an Estonian industrial sourdough, along with one commercial strain, L. plantarum TAK59 (Nordwise Biotech OÜ, Estonia), were included. EPS production by the strains was evaluated after cultivation in MRS broth with 2% sucrose, followed by isolation and quantification using gravimetric and phenol–sulfuric acid assays. The EPS produced exhibited glucose-equivalent sugar contents ranging from 278.3 to 362.8 µg/mg and yields of 131.4–225.2 mg/L. The highest sugar content was observed in L. plantarum strain A44, whereas the greatest EPS yield was recorded for strain A37. The commercial strain TAK59 yielded the lowest EPS dry mass and productivity. No statistically significant differences were detected in sugar content or yield among individual strains or between genotypes (p > 0.05). Notably, differences were observed in the dry mass of lyophilized EPS. L. plantarum isolates A52 and A45, belonging to genotype G5, displayed significantly lower dry mass compared to other genotypes (p < 0.05), except for G6 (L. plantarum isolates A51 and A44), for which differences were not statistically significant. Similarly, no linear correlation was observed between sugar content and dry matter (R²=0.0177), suggesting that these two quantification methods are not directly comparable and likely capture different characteristics of the EPSs, such as purity, composition, or structural variability of the polysaccharides. In conclusion, all L. plantarum strains assessed in this study demonstrated substantial EPS-producing capacity. The results contribute to valorizing sourdough biodiversity and support the development of tailored starter cultures for enhancing bread quality and functional potential. The long-term propagation of these sourdoughs has likely driven strain-specific adaptations, making them valuable sources of technologically and functionally distinct EPS producers compared to commercial starters. Future research should focus on optimizing cultivation conditions (medium composition, pH, temperature, incubation time, nutrient availability) to maximize EPS yield and enable targeted applications in improving the texture, stability, and functionality of fermented foods.
  • Pisipilt
    Kirje
    Toiduainete tehnoloogia
    (Audiomeister, 2017) Poikalainen, Väino; Laikoja, Katrin; Traksmaa, Anna; Laos, Katrin; Lepasalu, Lembit; Soidla, Riina; Andreson, Helena; Veri, Kristiina; Mahla, Tauno; Tatar, Vilma; Tatar, Vilma (koostaja); Tatar, Vilma (koostaja)
    Toiduainetööstus annab suure osa Eesti rahvuslikust koguproduktist ja on toidu tooteahelas (toore-töötlemine-turustus) kõige olulisemaks lisandväärtuse loojaks. Sellele vaatamata puudub senini eestikeelne toiduainete tehnoloogia kõrgkooliõpik, mis sisaldaks süsteemselt esitatud baasteadmisi: • loomse- ja taimse toorme omadustest, koostisest jms, • toidutoorme töötlemise füüsikalis-keemilistest ja bioloogilistest põhiprotsessidest, • olulisemate toiduainete tehnoloogiatest. Eestikeelne toiduainete tehnoloogia õppekirjandus on senini lünklik, käsitleb eraldi kitsaid teemasid ega moodusta ühtset tervikut. See asjaolu raskendab üliõpilaste õppetööd, spetsialistide täiendkoolitust ja üldiste töötlemispõhimõtete tutvustamist ka laiemalt toidu tooteahelas. Koostatud õpik on mõeldud eelkõige toiduainete tehnoloogia alaste baasteadmiste omandamiseks bakalaureuseõppes ja edaspidi jääb aluseks praktiliste õppevormide (labortööd, praktikumid) ning erinevate e-õppe materjalide, õppevideote jms süsteemsel väljatöötamisel. Õpiku olemasolu võimaldab suurendada toiduainete tehnoloogia bakalaureuseõppe üliõpilaste iseseisva töö mahtu ja muuta kogu õppeprotsessi efektiivsemaks. Selleks, et toiduainete valmistamine toimuks efektiivselt, on vajalik tunda nii toidutoorme koostist ja omadusi kui võimalikke töötlemise meetodeid ja tehnilisi lahendusi. Koostatav õpik on vajalik infoallikas ka toiduainete tööstustele, kuna toiduainete töötlemine (tehnoloogia) on suhteliselt keeruline, mitmekülgseid baasteadmisi eeldav valdkond. Peale selle soodustab õpik ühtse eestikeelse erialaterminoloogia juurdumist ning on kasulik infoallikas vastavatele hobirühmadele ja toiduainete tarbijatele kui toidu tooteahela sihtgrupile.